According to new studies released in the American Journal of Clinical Nutrition, a clinical trial conducted by researchers at Tufts University in Boston revealed that adults who consumed a diet rich in whole grains rather than refined grains had modest improvements in healthy gut microbiota and certain immune responses. The research was conducted in tandem with a study that looked at the effects of a whole-grain diet on energy metabolism, suggesting that substituting grains increases caloric loss by reducing calories retained during digestion and speeding up metabolism.
During an eight week period, 81 men and women between the ages of 40-65 were split into two groups. For the first two weeks, both groups enjoyed comparable meals, based on total energy, fat, and number of fruit, vegetable, and protein servings, including only refined grains (such as white flour, white rice, and white bread). Refined grains are starches that have been processed and broken down into a finer texture, primarily to increase shelf life. By the third week, 41 participants switched from refined to whole grains (those which include the outer nutritious layer of grains, found in products such as whole-wheat flour, oatmeal and brown rice) for the remainder of the study. (more…)